I've been away from diving for a decade. What major discoveries have occurred in dive medicine and decompression theory since I left?

[mathematics]

See the thread title. Last thing I remember, before aforementioned ten year coma, was the study showing that Pyle stops tended to skew outcomes towards DCS. Now, I come back and nobody's using VPM-B or RGBM, and we're all doing Buhlmann again, so clearly something happened. Did we answer any big questions? Did we knock down any big hypotheses? Did we see any new pathologies? Why is Rubicon Foundation still down? Haven't they been down for a decade now? I'm so confused, so please confuse me better. Thanks.

 

[34109411]

google

 

[Jonn]

Hemlines go up, then they go down. Wind blows east, then blows west. Deep stops are good, then they’re bad. Why?
Answers do exist, you can draw a line of causation between events if you look close enough, but sometimes the most correct explanation is “just because”.

 

[mathematics]

google

I watched RF4 and the conclusion I got was that basically nothing has changed.

 

[Nick_Radov]

See the thread title. Last thing I remember, before aforementioned ten year coma, was the study showing that Pyle stops tended to skew outcomes towards DCS. Now, I come back and nobody's using VPM-B or RGBM, and we're all doing Buhlmann again, so clearly something happened. Did we answer any big questions? Did we knock down any big hypotheses? Did we see any new pathologies? Why is Rubicon Foundation still down? Haven't they been down for a decade now? I'm so confused, so please confuse me better. Thanks.

The major advance in the past 10 years is that we now all use our midi-chlorian levels to plan deco. Those of us with high counts are able to safely run much shorter deco schedules.

Gradient Factors in a Post-Deep Stops World

World-recognized decompression physiologist and cave explorer David Doolette explains the new evidence-based findings on “deep stops,” and shares how and why he sets his own gradient factors. His recommendations may give you pause to stop (shallower).

indepthmag.com

 

[Mobulai]

confuse me better.

I’ll borrow this phrasing

 

[Wibble]

Deep stops out.
Bubble models out.
Bulhmann in.
Gradient Factors around 50:75 in.
Gas densities in.
Helium scarce and very expensive.
Rebreathers in.
Deep open circuit out.
Ratio deco out (except for some laggards)
Shearwater computers are the standard.

 

[boulderjohn]

Here is a summary of the change in thinking.

 

[ancient diver]

I think you pretty much "inherit" a particular decompression algorithm when you buy your dive computer. Different manufacturers use different algorithms. Since there aren't any agreed upon standards, its pretty much up to software programs and the dive computer manufacturer's decisions on algorithms. As usual, if you have a preference, caveat emptor.

This 2018 study compares algorithms and might answer so9me of your questions:

Validation of algorithms used in commercial off-the-shelf dive computer - PMC

Whilst the US Navy has been very systematic about validating Navy dive computer algorithms, there has been little documented or published evidence of rigorous testing of the algorithms in commercial off-the-shelf dive computers. This paper reports ...

pmc.ncbi.nlm.nih.gov

If you use tables instead of a computer, you inherit the algorithms used to develop the tables. NOAA, PADI, NAUI, CMAS

It seems to me that a great deal of the discusion is driven by the technical diving, deep and planned decompression diving community which has gone to Buhlmann because you can tailor or optimise the model's gradient factors to fit your planned dive profile.

The average recreational divers I see here in Bonaire basically set their computer's O2 fraction, O2 pp limit, decide if they want to use conservative settings, follow their dive computers and stick to NDL's. Their understanding of which algorithm, gradient factors, RGBM, etc just isn't there. Dive computers have made it pretty much "monkey-bannana" for recreational NDL divers.

here's some reading material on where the USN and the Swedish military are. As usual, the USN used a different algorythm, tested with actual divers, and used empirical data to derive their latest tables.

https://apps.dtic.mil/sti/pdfs/ADA561928.pdf

 

[rx7diver]

... here's some reading material on where the USN and the Swedish military are. As usual, the USN used a different algorythm, tested with actual divers, and used empirical data to derive their latest tables.

https://apps.dtic.mil/sti/pdfs/ADA561928.pdf

March 2012 published date! There's nothing more recent than this?

rx7diver